With the rapid development of the Internet and the popularization of large screen multi-function mobile phones, a large quantity of mobile data multimedia services and various broad bandwidth multimedia services, such as the video conference, TV broadcast, video on demand, video advertisement, online education, and interactive games, etc., have emerged, which not only satisfy the continuously increasing service demands of mobile users, but also bring new service increasing points for mobile operators. These mobile data multimedia services requires that multiple users can receive the same data at the same time, and compared with general data services, they have characteristics such as large data amount, long duration, and delay sensitivity etc. For the purpose of efficiently utilizing mobile network resources, the 3rd Generation Partnership Project (3GPP) puts forward the MBMS service, which is a technique for transmitting data from one data source to multiple destinations, and which implements sharing of network (including the core network and access network) resources, and increases the utilization ratio of network resources (especially the air interface resources). The MBMS service defined in the 3GPP not only can implement multicast and broadcast of pure text and low speed messages, but also can implement broadcast and multicast of high speed multimedia services, and provides various abundant video, audio and multimedia services, which undoubtedly complies with the developing trend of future mobile data, and provides a better service prospect for the development of the 3rd Generation (3G).
In the LTE system, transmission of the MBMS service on the air interface is classified into two modes: the dedicated carrier and the mixed carrier, and a significant difference between these two transmission modes lies in that in the dedicated carrier mode, the carrier only carries the MBMS service; while in the mixed carrier mode, the carrier not only carries the MBMS service, but also carries the non MBMS service (e.g., the unicast service). As such, in the process of carrying the MBMS service in the mixed carrier mode, there may be the situation that two types of services are multiplexed on the same carrier. In order that these two types of services do not interfere with each other and have the maximum efficiency during transmission of the services, in the process of carrying the MBMS service and non MBMS service by using a mixed carrier in the LTE, the two types of services apply Time-Division Multiplexing (TDM).
In a MBSFN area, certain physical resources are allocated by a MBMS resource configuration method to carry the MBMS service in the MBSFN area. As shown in FIG. 1, the subframes filled with oblique lines denote the resources allocated to the MBMS service in a certain MBSFN area by using the existing MBMS service resource allocation scheme.
In a LTE system, MBSFN areas are allowed to overlap the same geographical location, the service contents in the MBSFN areas are different, and the physical resources for carrying the MBMS service allocated to the MBSFN areas are different. The physical channel formed by the physical resources for transmitting the MBMS service in each MBSFN area is called Physical Multicast Channel (PMCH), which is used to carry a Multicast Channel (MCH). As shown in FIG. 2, there are 2 MBSFN areas (the bold border line represents the area border) in all, namely MBSFN area ID1 and MBSFN area ID2 (respectively referred to as MBSFN ID1 and MBSFN ID2 for short in this disclosure). The coverage area of MBSFN ID1 includes the area of MBSFN ID2, that is, the overlapped coverage area of MBSFN ID1 and MBSFN ID2 is the area of MBSFN ID2. For the cells in the area of MBSFN ID2, there are 2 overlapped MBSFN areas. According to the existing MBMS resource allocation scheme, resource allocation as shown in FIG. 3 can be provided. The subframes filled with left oblique lines denote the physical resources allocated to MBSFN ID1, and the subframes filled with right oblique lines denote the physical resources allocated to MBSFN ID2, that is, different physical resources are allocated to different MBSFN areas to ensure that the physical resources in the areas are not overlapped. As such, conflict of data from different MBSFN areas can be avoided, which is one of the objects of the existing scheme design.
In the LTE (also called 3GPP Release 8), the design of the Multicast Control Channel (MCCH) is preliminarily divided into a Primary Multicast Control Channel (P-MCCH) for carrying the Primary Multicast Control Channel signaling; and a Secondary Multicast Control Channel (S-MCCH) for carrying the Secondary Multicast Control Channel signaling. In this disclosure, without further explanation, the MCCH channel is used to carry MBMS control signaling, and therefore, the MCCH represents the MBMS control signaling carried on the MCCH. The scheduling information of one or two P-MCCHs is indicated in a Broadcast Control Channel (BCCH). One is single-cell mode transmission and is transmitted on a Downlink Shared Channel (DL-SCH), and the other is multi-cell mode transmission and is transmitted on the MCH. It should be noted that the concepts of single-cell mode transmission and multi-cell mode transmission in this patent application come from the definitions in chapter 15.3.2 Single-cell transmission and chapter 15.3.3 Multi-cell transmission in the LTE protocol 36.300v870.
In the single-cell mode transmission, each cell transmits MCCH information independently, the MCCH is mapped to the Downlink Shared Channel (DL-SCH) to be carried, and MCCHs of adjacent cells do not perform MBSFN combination; while in the multi-cell mode transmission, the MCCH is mapped to the MCH, each cell in the MBSFN area transmits MCCH information of the same content on the same time and frequency resources simultaneously, and the MCCHs of adjacent cells perform MBSFN combination. The P-MCCH in multi-cell mode transmission is similar.
If the MCCH is not divided into the primary and secondary ones, then both of the Primary Multicast Control Channel signaling and the Secondary Multicast Control Channel signaling are carried on the MCCH.
In a MBSFN area, it is required that the cells in the same MBSFN area transmit data of the same format and content on the same time and frequency resources, namely implementing the MBSFN combination, so as to improve the receiving performance of the terminal, eliminate the hand-off operation of the terminal when the terminal moves in the MBSFN area, and greatly reduce the overhead of signaling. As shown in FIG. 2, when MBSFN areas (such as the MBSFN ID1 and MBSFN ID2) are overlapped, the prior art does not give an operable method regarding how to form the broadcast and multicast service control signaling, how to transmit the broadcast and multicast service control signaling, and ensure that the control signaling belonging to the areas of MBSFN ID1 and MBSFN ID2 can also perforin the MBSFN combination at the border of the overlapped area to realize that the control signaling can perform the MBSFN combination in all the valid areas, and ensure the effectiveness of control signaling transmission, that is, the control signaling is not transmitted when there is no MBMS service.